Yes, they are compatible. The HP Photosmart 5520 e-All-in-One printer uses HP 364 ink. HP 364XL ink is for 750 pages, the HP 364 for 300 pages. But it has no influence on the durability.
Article 15664282 is compatible with the following devices:
- DeskJet 3520 e-All-in-One Series
- Photosmart 7510 e-All-in-One Series
- Photosmart 7520 e-All-in-One Series
- Photosmart B8550 Series
- Photosmart C5300 All-in-One Series
- Photosmart C6300 All-in-One Series
- Photosmart D5400 Series
Item 208167 is compatible with the following devices:
- HP Photosmart 7520 e-All-in-One Printer (CZ045B)
All compatible devices are listed on the manufacturer's website: https://store.hp.com/SwitzerlandStore/Merch/Product.aspx?id=N9J73AE&opt=&sel=SUP&lang=de-CH&gclid=EAIaIQobChMIhP7CiMeb3AIVr53tCh1VhQ6aEAQYAyABEgJp0fD_BwE&gclsrc=aw.ds&dclid=CJnYx5LHm9wCFZfhGwodEREOJg
Yes, the cartridges are for the HP Photosmart Premium C310a. Correct, the black colour is wider than the colour.
https://h22203.www2.hp.com/SureSupply/?searchTerm=HP-Photosmart-Premium-e-All-in-One-Printer---C310a
According to HP's cartridge list, the cartridges with the designation 950 XL must be purchased for the HP Officejet 8600 plus - my ink cartridges have the designation 364XL for the black ink.